Re: string manipulation : removing a part of a string

[Vincent Torri]

On Mon, 18 Jun 2012, Eric Blake wrote:

> On 06/16/2012 12:01 AM, Vincent Torri wrote:
> > On Fri, 15 Jun 2012, Eric Blake wrote:
> >
> > > On 06/15/2012 04:55 PM, Vincent Torri wrote:
> >
> > > > AC_DEFUN([EFL_CHECK_COMPILER_FLAG],
> > > > [
> > > > m4_pushdef([UPEFL], m4_translit([[$1]], [-a-z], [_A-Z]))
> > > > m4_pushdef([UP], m4_translit([[$2]], [-a-z], [_A-Z]))
> > > >
> > > > m4_if(m4_index([$2], [-Wno-]), [0], [m4_pushdef([flagm4],
> > > > [m4_bpatsubst([[$2]], [no-])])], [m4_pushdef([flagm4], [$2])])
> > >
> > > option=m4_bpatsubst([[$2]], [no-])
> >
> > Actually, i want to store in option -Wfoo if $2 is -Wno-foo, and only
> > that case. It's for testing if a compiler option is available (after
> > discussion with gcc guys, -Wno-foo use produces a warning while -Wfoo
> > use produces an error). So if I pass -fno-bar, option will store -fbar,
> > which is not what I want. So I guess that I have to use the m4_if
> > construction.
>
> But you can still be shorter than using a pushdef:
>
> option=m4_bpatsubst([[$2]], [^-Wno-], [-W])

does not work. Removing ^ seems to work

thank you

Vincent Torri